JPH04328551A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To improve exposure visible picture property and enhance photosensitivity by incorporating ortho-quinone diazo compound, specified compound, dystuff changing tone by mutual reaction with a photodissociated product of the compound and inorganic acid. CONSTITUTION:An ortho-quinone diazide compound, a compound forming acid or radicals by irradiating it with activated ray, a dystuff changing tone by mutual reaction with a photo-dissociated product and inorganic acid. As examples of inorganic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, HBr, HI, H3BO3, HClO4, HClO3, HIO3, HIO4, H3AsO3, etc., are given, and one or not less than two kinds of these acids are used upon mixing. As examples of compounds forming acid or radicals by irradiating them with activated ray, halomethyl oxiadiazol compound, halomethyl-s-triazine compounds, etc., are given.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition that can be used in a photosensitive lithographic printing plate, and more particularly to a photosensitive composition that has good exposure and visible imageability and high sensitivity.

0002

[Prior Art] A photosensitive lithographic printing plate is one in which an ink-receptive photosensitive layer is provided on a hydrophilic support. For example, in a positive-working photosensitive lithographic printing plate, ultraviolet rays, etc. An ink-receptive photosensitive layer is formed which becomes solubilized by exposure to actinic light. When the photosensitive layer of such a positive-working photosensitive lithographic printing plate is subjected to imagewise exposure and then developed, the photosensitive layer in the exposed areas is removed and the surface of the hydrophilic support is exposed, while the photosensitive layer in the unexposed areas is It remains on the support to form an ink-receiving layer.

[0003] In planographic printing, the difference in properties is utilized in that the exposed areas are hydrophilic and the unexposed areas are lipophilic.

Usually, the photosensitive layer of a positive photosensitive lithographic printing plate contains an o-quinonediazide compound as a photosensitive component and an alkali-soluble resin as a component for increasing film strength and alkali solubility.

These photosensitive planographic printing plates are required to have high sensitivity in order to improve workability.

[0006] For this reason, particularly among the o-quinonediazide compounds mentioned above, 1,2-naphthoquinone-2-diazide-5-sulfonic acid ester compounds are generally used as being useful from the viewpoint of sensitivity and cost.

[0007] In plate making, exposure operations such as so-called "multi-sided printing" are performed, in which a plurality of film originals are printed one after another while changing their positions. In these exposure operations, if it is not possible to distinguish between exposed areas and unexposed areas, the position of the exposed areas cannot be confirmed, making the exposure operations difficult and leading to incorrect exposure. In order to avoid these problems, photosensitive compositions are required to form a visible image upon exposure that can be recognized even under the yellow safety light used for exposure work (exposure visible image property). ing.

[0008] In order to obtain exposure-visible imageability, photosensitive compositions have been incorporated with printout materials that form visible images upon exposure. The printout material is composed of an organic dye that changes its color tone by interacting with a compound that generates an acid or a free radical when exposed to light. Trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A-36223, halomethyl-2-pyrone and trihalomethyl-triazine described in JP-A-55-77742.
Examples include vinyl-oxadiazole compounds and diazonium salts.

[0009] However, it has been found that when the amount of these conventionally known compounds that generate acids or free radicals upon exposure to light is increased, the sensitivity decreases.

0010

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems to be solved, and its object is to provide a photosensitive composition that has good exposure visibility and high sensitivity. There is a particular thing.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the photosensitive composition of the present invention comprises (a) an orthoquinone diazide compound, (b) a compound that generates an acid or a free radical upon irradiation with actinic rays, (c) a dye that changes its color tone by interacting with the photolysis product of (b); and (
d) It is characterized by containing an inorganic acid.

Examples of inorganic acids used in the present invention include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, HBr, HI, H3B
O3, HClO4, HClO3, HIO3, HIO4,
Examples include H3AsO3. Particularly preferred are sulfuric acid and phosphoric acid.

[0013] These inorganic acids are used singly or in combination of two or more, and the amount of these inorganic acids is from 0.01 to
It is used in an amount of 5 wt%, more preferably 0.05 to 2 wt%. If the amount of inorganic acid added in the present invention is too small, the effects of the present invention cannot be obtained, and on the other hand, if the amount added is too large, the visible image after exposure may become difficult to see, or the image area may be easily damaged during development. or

The photosensitive composition of the present invention contains compounds that generate acids or free radicals upon irradiation with actinic rays, such as halomethyloxadiazole compounds, halomethyl-s
- Triazine compounds and the like are used.

[0015] What is a halomethyloxadiazole compound?
It is a compound having a halomethyl group, preferably a trichloromethyl group, in the oxadiazole ring.

These compounds are known, for example, in Japanese Patent Publication No. 57-6096, Japanese Patent Publication No. 61-51788,
Japanese Patent Publication No. 1-28369, Japanese Patent Application Publication No. 1983-13853
Publication No. 9, Publication No. 60-177340, Publication No. 60-24
It is described in Publication No. 1049 and the like.

The halomethyloxadiazole compounds preferably used in the present invention are specifically shown below, but the halomethyloxadiazole compounds used in the present invention are not limited thereto.

[0018]

[Chemical formula 1]

[0019]

[Case 2]

[0020]

[Chemical formula 3]

Further, the halomethyl-s-triazine compound is a compound having one or more halomethyl groups, preferably trichloromethyl groups, in the s-triazine ring.

These compounds are known, for example, Japanese Patent Publication No. 60-46700, Japanese Patent Publication No. 62-44258,
Japanese Patent Publication No. 1-28369, Japanese Unexamined Patent Publication No. 58-87553
No. 60-239736, No. 60-239
No. 473, No. 61-151644, No. 62-
No. 24242, No. 62-58241, No. 62
It is described in JP-A-175735, JP-A No. 63-58440, JP-A No. 63-298339, etc.

These compounds can be used in the present invention.

Next, halomethyl-s-triazine compounds preferably used in the present invention will be specifically shown, but the halomethyl-s-triazine compounds used in the present invention are not limited to these.

[0025]

[C4]

[0026]

[C5]

[0027]

[C6]

The amount of the compound that generates acid or free radicals upon irradiation with active light in the photosensitive composition of the present invention is preferably 0.01 to 10% by weight, more preferably 0.1 to 30% by weight. % by weight, particularly preferably 0.
It is 2 to 3% by weight.

The pigments used in the present invention that change their color tone by interacting with the photodecomposition products of compounds that generate acids or free radicals upon irradiation with actinic rays include those that develop color and those that fade or change color. There are two types: As the pigment that fades or changes color, various pigments such as diphenylmethane, triphenylmethane-based thiazine, oxazine-based, xanthene-based, anthraquinone-based, iminonaphthoquinone-based, and azomethine-based dyes are effectively used.

Specific examples of these include the following. brilliant green, eosin,
Ethyl violet, erythrosine B, methyl green, crystal violet, basic fuchsin, phenolphthalein, 1,3-diphenyl triazine, alizarin red S, thymol phthalein, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol Sulfophthalein, xylenol blue, methyl orange, orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, paramethyl red, Congo red, benzopurpurin 4
B, α-naphthyl red, Nile Blue 2B, Nile Blue A, phenacetarin, methyl violet, malachite green, parafuchsin, Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue #60
3 [manufactured by Orient Chemical Industry Co., Ltd.], Oil Pink #3
12 [manufactured by Orient Chemical Industry Co., Ltd.], Oil Red 5
B [manufactured by Orient Chemical Industry Co., Ltd.], Oil Scarlet #308 [manufactured by Orient Chemical Industry Co., Ltd.], Oil Red OG [manufactured by Orient Chemical Industry Co., Ltd.], Oil Red RR [manufactured by Orient Chemical Industry Co., Ltd.] , Oil Green #502 [manufactured by Orient Chemical Industry Co., Ltd.], Spiron Red BEH Special [manufactured by Hodogaya Chemical Industry Co., Ltd.]
, m-cresol purple, cresol red, rhodamine B, rhodamine 6G, fast acid violet R, sulforhodamine B, auramine, 4-p-diethylaminophenylimino naphthoquinone, 2-carboxyanilino-4-p-diethylaminophenylimino naphthoquinone, 2-carbostearylamino-4-p-
dihydroxyethylamino-phenylimino naphthoquinone, p-methoxybenzoyl-p'-diethylamino-o'-methylphenyliminoacetanilide, cyano-p-diethylaminophenyliminoacetanilide,
1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4
-p-diethylaminophenylimino-5-pyrazolone.

[0031] Arylamines can also be used as coloring pigments. Arylamines suitable for this purpose include not only simple arylamines such as primary and secondary aromatic amines, but also so-called leuco dyes, examples of which include the following.

Diphenylamine, dibenzylaniline,
Triphenylamine, diethylaniline, diphenyl-
p-phenylenediamine, p-toluidine, 4,4'-
biphenyldiamine, o-chloroaniline, o-bromoaniline, 4-chloro-o-phenylenediamine, o-
Bromo-N,N-dimethylaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, aniline, 2,5-dichloroaniline, N
-methyldiphenylamine, o-toluidine, p,p'
-Tetramethyldiaminodiphenylmethane, N,N-dimethyl-p-phenylenediamine, 1,2-dianilinoethylene, p,p',p''-hexamethyltriaminotriphenylmethane, p,p'-tetramethyldiaminotri Phenylmethane, p,p'-tetramethyldiaminodiphenylmethylimine, p,p',p''-triamino-
o-methyltriphenylmethane, p,p',p''-triaminotriphenylcarbinol, p,p'-tetramethylaminodiphenyl-4-anilinonaphthylmethane,
p, p', p''-triaminotriphenylmethane, p,
p',p''-hexapropyltriaminotriphenylmethane.

The proportion of the above dye in the photosensitive composition is preferably 0.01 to 10% by weight, more preferably 0.02 to 5% by weight.

In the photosensitive composition of the present invention, a positive type photosensitive substance, orthoquinone diazide compound, is used as the photosensitive substance.

The orthoquinonediazide compound preferably used in the present invention includes a reaction product of a compound containing an orthoquinonediazide group and an alkali-soluble resin.

Typical reaction products of compounds containing orthoquinonediazide groups and alkali-soluble resins include ester compounds of o-naphthoquinonediazide sulfonic acid and polycondensation resins of phenols and aldehydes or ketones. It will be done.

Examples of the phenols used in the production of the polycondensation resin of phenols and aldehydes or ketones that form such ester compounds include phenols, o
-cresol, m-cresol, p-cresol, 3,
Examples include monovalent phenols such as 5-xylenol, carvacrol, and thymol, divalent phenols such as catechol, resorcinol, and hydroquinone, and trivalent phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these aldehydes are formaldehyde and benzaldehyde. In addition, examples of ketones include acetone,
Mention may be made of methyl ethyl ketone.

Specific examples of the polycondensation resins include phenol/formaldehyde resin, m-cresol/formaldehyde resin, m-, p-mixed cresol/formaldehyde resin, resorcinol/benzaldehyde resin, and pyrogallol/acetone resin. .

These polycondensation resins of phenols and aldehydes or ketones can be produced by known methods.

The condensation rate (reaction rate for one OH group) of the phenol of the compound containing the orthonaphthoquinone diazide group is preferably 15 to 80%, more preferably 20 to 60%.

[0041] Also, as a reaction product of a compound containing an orthoquinonediazide group and an alkali-soluble resin, o-
An ester compound of naphthoquinonediazide sulfonic acid and a vinyl polymer having a phenolic hydroxyl group can also be used.

[0042] Vinyl polymers having phenolic hydroxyl groups that form such esters are disclosed in Japanese Patent Application No.
A vinyl polymer having a phenolic hydroxyl group described in No. 29709 can be used.

In addition, compounds containing an orthonaphthoquinonediazide group and 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,2',4'-pentahydroxy Condensation compounds with benzophenone, 2,3,4,3',4',5'-hexahydroxybenzophenone can also be used.

In the photosensitive composition of the present invention, an alkali-soluble resin is further used.

Examples of the alkali-soluble resins include novolac resins, vinyl polymers having phenolic hydroxyl groups, and condensation resins of polyhydric phenols and aldehydes or ketones described in JP-A-55-57841. , these resins can also be used in combination.

Examples of the novolak resin include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-57841, and JP-A-55-127553. Examples include p-substituted phenol/phenol or cresol/formaldehyde copolycondensation resins as described in Japanese Patent Publication No.

Examples of non-novolac resins include vinyl polymers having phenolic hydroxyl groups, particularly vinyl polymers having units having phenolic hydroxyl groups in their molecular structure.

These alkali-soluble resins preferably have a weight average molecular weight of 1,000 or more, more preferably 1,500 or more, in view of coating properties.

Other additives commonly used in these photosensitive compositions can be added to the photosensitive composition of the present invention, if necessary.

The photosensitive composition of the present invention is prepared by dissolving each of these components in the following solvents, coating the solution on the surface of a suitable support, and drying it to form a photosensitive layer.
A photosensitive lithographic printing plate can be formed.

Solvents that can be used to dissolve each component of the photosensitive composition of the present invention include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, methyl carbitol, and ethyl carbitol. , diethylene glycol ethers and/or esters such as dimethyl carbitol, diethyl carbitol, methyl carbitol acetate, dimethyl-3-methoxy-1-butanol, propylene glycol monomethyl ether, propylene glycol dimethyl ether, methyl ethyl ketone, formamide, dimethyl sulfoxide, dioxane, acetone,
Examples include cyclohexanone, trichloroethylene, and methyl ethyl ketone. These solvents can be used alone or in combination of two or more.

In the present invention, it is preferable to use alkyl ethers of dialkylene glycol, such as dimethyl carbitol, alone or in combination with other solvents. At this time, it is preferable that the amount of the alkyl ether of dialkylene glycol to be mixed exceeds 15% by weight. Furthermore, the content is preferably over 40% by weight, particularly preferably 55% by weight or more.

The coating method used for applying the photosensitive composition of the present invention to the surface of a support includes conventionally known methods, such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, and blade coating. It is also possible to use curtain coating, etc. The coating amount varies depending on the application, but is preferably, for example, 0.1 to 5.0 g/m2 (as solid content). In addition, the drying temperature is, for example, 20~
A temperature of 150°C, preferably 30 to 100°C is employed.

[0054] In the present invention, the amount of the photosensitive coating liquid to be applied onto the support varies depending on the use, but it is generally appropriate to have a solid content of 0.5 to 3.5 g/m2.

Supports on which the photosensitive layer using the photosensitive composition of the present invention is provided include metal plates such as aluminum, zinc, steel, and copper, as well as metal plates plated or plated with chromium, zinc, copper, nickel, aluminum, iron, etc. Examples include vapor-deposited metal plates, paper, plastic films, glass plates, paper coated with resin, paper covered with metal foil such as aluminum, and hydrophilic plastic films. Among these, aluminum plates are preferred. As a support for a photosensitive lithographic printing plate using the photosensitive composition of the present invention, it is preferable to use an aluminum plate that has been subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. preferable.

[0056] Known methods can be applied to these treatments.

A photosensitive lithographic printing plate using the photosensitive composition of the present invention can be developed by a conventional method. For example, the transparent positive film is exposed to light from a light source such as an ultra-high pressure mercury lamp, metal halide lamp, xenon lamp, or tungsten lamp, and then developed with various alkaline developers. As a result, only the unexposed portion remains on the surface of the support, forming a positive-positive relief image.

Examples of the alkaline developer include alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tribasic sodium phosphate. Examples include aqueous solutions of. The concentration of the alkali metal salt is preferably 0.1 to 20% by weight. Furthermore, an anionic surfactant, an amphoteric surfactant, and an organic solvent such as alcohol can be added to the developer as required.

[0059]

[Examples] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples unless the gist of the invention is exceeded.

Example 1 [Preparation of aluminum plate] A 0.24 mm thick aluminum plate (material 1050, tempered H16) was degreased in a 5% by weight aqueous sodium hydroxide solution at 60°C for 1 minute. After that, in 1 liter of 0.5 molar hydrochloric acid aqueous solution, the temperature was 25°C, the current density was 60 A/dm2, and the treatment time was 30.
Electrolytic etching treatment was performed under conditions of seconds. Next, after desmutting in a 5% by weight aqueous sodium hydroxide solution at 60°C for 10 seconds, anodization was performed in a 20% by weight sulfuric acid solution at a temperature of 20°C, a current density of 3A/dm2, and a treatment time of 1 minute. processed. Furthermore, hot water sealing treatment was performed for 20 seconds with hot water at 80° C. to produce an aluminum plate as a support for a lithographic printing plate.

[Coating of photosensitive composition coating solution] Photosensitive composition coating solution 1 having the following composition was applied to the aluminum plate prepared as above using a rotary coating machine, and dried at 90° C. for 4 minutes. A positive photosensitive lithographic printing plate (Sample 1) was prepared.

The thickness of the dry coating film of this sample was 2.2 g/
It was m2.

(1 composition of photosensitive composition coating solution) (1) o-
Naphthoquinone diazide compound (QD-1)
1.8 g (2) Novolac resin (1)

2.5 g (3) non-novolac resin (2)
4.3
g(4) Halomethyloxadiazole compound (rad
-1) 0.07g (5) Pigment (Victoria Pure Blue BOH) (manufactured by Hodogaya Chemical)
0.07g (6) Methyl cellosolve

100ml (7) Sulfuric acid

0.4 g

[0064]
Example 2 Photosensitive composition coating liquid 2 was prepared in the same manner as in Example 1 except that phosphoric acid was used instead of sulfuric acid in the composition of photosensitive composition coating liquid 1 of Example 1. A positive-working photosensitive lithographic printing plate sample 2 was prepared.

Comparative Example 1 Photosensitive composition coating solution 3 was prepared in the same manner as in Example 1 except that sulfuric acid was not added to the composition of photosensitive composition coating solution 1 of Example 1. Positive-working photosensitive lithographic printing plate sample 3 was prepared.

Comparative Example 2 In the photosensitive composition coating solution 1 composition of Example 1, sulfuric acid was not added, and a halomethyloxadiazole compound (
A photosensitive composition coating solution 4 was prepared in the same manner as in Example 1 except that 0.14 g of rad-1) was added instead of 0.07 g, and this was used to prepare a positive photosensitive lithographic printing plate. Sample 4 was produced.

[0067]

[Chemical 7] Novolac resin (1) Phenol, m-cresol, p
- Copolymer compound of cresol and formaldehyde (the molar ratio of phenol, m-cresol and p-cresol is 20:48:32, Mw=6000, Mw/M
n=5.0)

[0068]

[Chemical formula 8]

<Evaluation of sensitivity> Each of the obtained photosensitive lithographic printing plate samples 1 to 4 was coated with a step tablet for sensitivity measurement (
Eastman Kodak No. 2.Difference in concentration 0.15
(21 levels of gray scale) in close contact with each other, 2kw
Exposure was carried out from a distance of 90 cm using a metal halide lamp (Idol Fin 2000 manufactured by Iwasaki Electric Co., Ltd.) as a light source. Next, this sample was developed at 27° C. for 20 seconds using a developer prepared by diluting SDR-1 (manufactured by Konica Corp.) six times with water.

Sensitivity was defined as the exposure time at which the 3.0 step of the step tablet was completely cleared.

<Evaluation of visible image quality upon exposure> The difference in density between the exposed and unexposed areas of the sample before development was exposed under the above conditions and was visually evaluated under a yellow lamp to evaluate the visible image quality upon exposure. Further, measurement was performed using a densitometer (Konica densitometer PDA-65), and the absolute value ΔD of the density difference between the exposed area and the unexposed area was determined. It is shown that the larger ΔD is, the better the exposure visible image quality is.

Table 1 shows the evaluation results of sensitivity and exposure visibility.

[0073]

[Table 1] *1 Exposure visible image property (visual observation) Good exposure visible image property was evaluated as ◯, and poor state as ×, and evaluated in 3 grades. ○ or above is a practical level. Exposure visible image properties (excellent)←○,△,×→(poor) From the results in Table 1, photosensitive lithographic printing plate samples 1 and 2 using the photosensitive composition of the present invention have good exposure visible image properties. It can be seen that the sensitivity is high.

On the other hand, Comparative Sample 3, which does not contain an inorganic acid, has poor exposure visible image properties, and Comparative Sample 4, which contains an increased amount of halomethyloxadiazole compound (rad-1), has poor exposure visible image properties. is improved to a practical level, but the sensitivity is reduced.

[0075]

As described above in detail, the photosensitive composition of the present invention makes it possible to provide a photosensitive lithographic printing plate with good exposed visible image properties and high sensitivity.

Claims (1)

[Claims] Claim 1: (a) an orthoquinonediazide compound;
(b) a compound that generates an acid or a free radical upon irradiation with actinic light, (c) a dye that changes its color tone by interacting with the photodecomposition product of (b), and (d) an inorganic acid. A photosensitive composition characterized by: